(1) Field of the Invention
The present invention relates to a filter cartridge for filtering fluids. More specifically, the present invention relates to a filter cartridge having utility, for example, in separating oil from an oil and compressed air mixture.
(2) Description of the Prior Art
Separators which remove liquid from liquid and gas mixtures are well known in the art. Such separators typically include a container having at least one cylindrical filter cartridge disposed therein and are often used to separate oil from oil and air mixtures. The oil and air mixture flows radially inwardly through the filtering material included in the cylindrical filter cartridge. The filtering material causes the finely divided atomized particles of oil to coalesce in comparatively large droplets which will be drained off into a sump for collection. The filtered air flows radially inwardly into an axial passage and the filtered air flow axially out of the cartridge.
The material used for filtering is critical to the ability of the filter cartridge to separate the oil from the oil and air mixture. It is known that a porous boro-silicate glass filter material is particularly suited for removing oil from an oil and air mixture. However, boro-silicate glass filtering material in sheet or paper form has a low density and is extremely succeptible to being crushed during manufacture and use of the filter cartridge. The boro-silicate glass filtering paper also abrades easily. Crushing of the boro-silicate glass filtering paper results in a substantial decrease in the ability of the material to separate oil from an oil and air mixture. Thus, while it is understood in the art that the boro-silicate glass paper would perform well as one of the filtering materials included in a cylindrical filter cartridge, until the present invention, this difficult to handle paper has not been employed in commercially available filter cartridges. There exist commercially available filter cartridges which use boro-silicate glass material which is molded into the desired form by an expensive molding process. Even the molding process tends to crush the boro-silicate glass fibers to that the molded form has inconsistent filtering capabilities throughout.
It is one object of the present invention to provide a filter cartridge which is highly efficient in removing oil from an air and oil mixture.
It is another object of the invention to provide a filter cartridge that can use low density, highly crushable filter paper such as boro-silicate glass paper.